So it's pretty obvious by the end of the game that each Bioshock multiverse is part of an even larger cosmos in which the same elements obtain:

A lighthouse that serves as a secret transit station to another realm.

A utopian, technologically superior society isolated from the rest of the world. (Rapture/Columbia)

A mad visionary founder/leader (who assumes a new identity over the course of his life) who eventually loses control of his city. (Ryan/Comstock)

A working class revolutionary opposed to the founder's regime, who, while apparently benevolent at first, is revealed to be a murderous thug. ("Atlas"/Fitzroy)

A challenger who, unbeknownst to himself and others, is the secret doppelgänger/son/pawn of the founder. (Jack/Booker)

Magical powers! (Plasmids/Vigors)

A young woman or girls who represent the secret power behind the society's existence. (Little Sisters/Elizabeth)

A quasi-mechanical "guardian" who loves and protects the girl(s), who is at the same time their jailer. (Big Daddies/Songbird)

A female scientist who is instrumental in creating the society, yet ends up undermining it by helping the protagonist. (Tenenbaum/Lutece)

An industrialist whose name starts with "F" whose influence and political power rivals the founder's. (Fontaine/Fink)

A sadistic doctor (Suchong/Powell)

A scene in which the protagonist (un)willingly murders his father-double.

The protagonist ultimately saves the girl(s) and is reunited with them at the ending; he raises them as his own children. ("Happy" Bioshock ending only.)

So far, so good. But I couldn't help noticing that there were a few nonequivalent elements that stood out. Lady Comstock, for example, is one of the characters who doesn't have a Rapture double. (Ryan has mistresses and girlfriends that we hear about, but none of them appear in the game.) She's actually pretty mysterious, since we never find anything about her personal life or background pre-Comstock; when Elizabeth brings her "back to life," she's just a sort of vague embodiment of malice and regret, literally a hole ripped in the fabric of reality. Also, the vigors don't have the addictive/degenerative quality of the plasmids in Bioshock; indeed, they don't seem to have any biological component at all, and their existence is never fully explained. And where Fontaine ended up being the same as the revolutionary who was opposed to his work, Fink ends up being murdered by his opponent (although "Fitzroy" also begins with an "F").

At any rate, I'm very interested in seeing where the series goes from here. I can't help but wonder what sort of environments and characters will figure in a sequel.

Anybody spot any other parallels or inconsistencies between the two games?